(former Basho engineer and committer on Riak and Antidote)

No, it's not Riak.

[Full disclosure: work was started in 2013/2014, with Basho, as an alternative to Riak and shares Riak Core as a base. At the time, Basho was a member of SyncFree.]

It's built on Riak Core, but it's a lot different from Riak in many ways: no replication in the DC, transactions, more data-types, operation-based CRDTs and not state-based CRDTs, log vs. in-place replacement in the storage backend.

I mean, the analogy is poor: it's even less close than saying that Riak is Cassandra and vice-versa.

I don’t think it’s Riak. It just uses riak_core, which is a kind of distribution / sharding framework. Riak itself has new owners and is not going away.